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    SubjectBuilding BarGraph with LED subsystem
    Hi all,
    I have a couple of questions about the (user-land) use of the LED subsystem.

    I recently offered a patch for controlling the LEDs of the G27 gaming
    wheel, on which the LEDs are arranged in a bar-graph of 5 to show
    simulation RPM. The suggestion was to use the LED subsystem, which this
    patch implements.

    Thinking further about how to about how to control this I was wondering
    whether a 'threshold' trigger would be useful. This would allow the use of
    value (uint?) to be compare against a threshold and the LED turned on/off

    The main benefit of doing this as a 'trigger' is that we could 'link' (or
    'sync') multiple LEDs to use the same value input, thus making the
    user-land stuff trivial.

    Concept - ledtrig-thres would provide the controls:
    threshold - value to compare against.
    value - incoming value, if >= threshold LED is lit, if < threshold LED
    is dark.
    link - 'none' (standalone comparison), or the path to the value of
    another LED's value to use (ie '/sys/leds/my_device::2/value')

    Comments? Is this all too complex?

    Also I have a question about the default permissions on the LED controls;
    Is it possible to register LEDs so that users have write permission? At
    present the controls are only accessible as root.

    Many thanks,

     \ /
      Last update: 2012-03-16 16:27    [W:0.020 / U:253.688 seconds]
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